Automatic packing

ABSTRACT

Packing spacer sheets are automatically fed one at a time to a pick-up station from a stack, with selected sheets arranged to arrive in inverted condition so that all packing sheets are properly oriented into packing position. Sheets can be pulled from stack by a transfer carrier having gripping jaws with teeth that dig into rib structures on sheet and jaws can open to engage other portions of sheet and thus hold the sheet to assure all teeth are pulled out of sheet. Stack can be a horizontal nesting of generally vertically disposed sheets carried by narrow spaced belts stepped along on a low friction surface with fixed retainer to stop forward face of stack and permit front sheet to be pulled off.

The present invention relates to packing, more particularly to thepacking of fragile articles with protective packing spacers.

Among the objects of the present invention is the provision of novelapparatus for use in the foregoing packing.

The above as well as additional objects of the present invention will bemore fully understood from the following description of several of itsexemplifications, reference being made to the accompanying drawingswherein:

FIG. 1 is a schematic plan view of a general arrangement for packingstraight fluorescent lamps pursuant to the present invention;

FIG. 2 is an enlarged front view of a detail of a packing feature in thepacking arrangement of FIG. 1;

FIG. 3 is a plan view of a packing sheet used in the packing arrangementof FIGS. 1 and 2;

FIG. 4 is an elevational view of one of the automatic feed units for thearrangement of FIG. 1;

FIG. 5 is an enlarged view with parts broken away, looking at the faceof the transfer conveyor of the apparatus of FIG. 4;

FIG. 6 is a more detailed elevational view similar to that of FIG. 4,showing portions of the second automatic feed unit looking at that unitfrom the rear;

FIG. 7 is a bottom plan view of some of the operating mechanism for theconstruction of FIG. 4; and

FIG. 8 is an enlarged detail of the sheet-gripping mechanism of theconstruction of FIG. 4 showing it gripping a warped portion of a sheet.

According to the present invention an automatic feed apparatus thatsupplies packing spacer sheets one at a time to a packing station, has astack holder that holds a stack of spacer sheets with the end spacer ofthe stack in a predetermined feed location, a transfer carrier shiftablymounted for movement between a first location adjacent saidpredetermined location for gripping the end spacer sheet and a secondlocation where it drops the gripped spacer sheet, a chute under thesecond location to catch the dropped spacer sheet and slide it downforwardly to a pick-up station, and sheet inverting means connected toautomatically invert a predetermined set of the spacer sheets so thatthey reach the pick-up station inverted side for side. The invertingmeans can include a first means for rotating the transfer carrier abouthalf a revolution around an axis generally perpendicular to the sheet sothat the rotated sheet drops into the chute rotated about 180° around aperpendicular axis, and additional means connected to flip the sheetover front-to-back as it moves down the chute.

A transfer carrier for gripping a molded fiber packing sheet having araised rib structure, desirably has, according to the present invention,a set of jaws shaped to engage the rib structure, the jaws havinggripping teeth that dig into the molded fiber of the rib structure whenthat structure is engaged by the ribs, and the jaws jointly float whenin engaged position so that they readily compensate for the dimensionalvariations inherent in molded pulp products, and opening structureconnected to open the jaws when a gripped sheet is to be released. Thejaws can also carry release-assisting projections extending in thegeneral direction in which the jaws open, to engage adjacent portions ofthe sheet when the jaws open and assure a positioning of the sheet thatcauses all the teeth to be pulled out of the molded fiber when the jawsare opened.

Another feature of the present invention is a stack holder that holds agenerally horizontally extending stack of generally verticlly disposedpacking sheets, a low friction elongated supporting surface for thestack, a plurality of high friction belts each less than about 1/2 inchwide having an upper flight extending along said supporting surface anda lower flight below said surface, the belts being spaced from eachother by at least two inches, advancing mechanism connected to advancethe belts and carry stacked packing sheets to one end of the supportingsurface, and fixed restraining elements at that end for engaging thefront of the stack by its edges, to keep the sheets from being pushedoff that end by the advancing mechanism, but permitting the front sheetof the stack to be pulled off.

Turning now to the drawings, the overall sequence of packing operationsinvolving the present invention is best seen in FIG. 1. A pair of arms10, 11 is arranged to carry a set of six fluorescent lamps 15 spacedside by side in a horizontal row. For this purpose the arms 10, 11 havetransverse grooves aligned so that each lamp rests in one of the grooveson each arm. The arms reciprocate together in the direction indicated bythe double-ended arrow 17 so that they retract from the illustratedposition to a loading position where they are below a series of thelamps at an inspection station 16 between inspecting mirrors 14, 14. Anindividual in charge of the packing can stand in front of the arms anduse these mirrors to determine that the terminal pins 19 at both ends ofeach lamp are not bent and remove those lamps that have bent terminals.The lamps are rolled into station 16 from a test station where theirterminal pins 19 are automatically engaged by electrical contacts thatcause the lamps to light if they are not defective.

In the loading position the empty arms are elevated with their frontends inclined upwardly to engage and lift a set of the lamps in theappropriate grooves after the inspection is completed, and then the armsare moved to the illustrated position where they hold the lamps in anessentially horizontal row over a lowering platform 20. At about thesame time a pair of packing sheets 21, 22 are moved from adjacent tables131, 132 and placed over the sides of the platform under the respectiveends of the lamps, an operation that is performed by hand. The arms 10,11 are then lowered slightly to leave the set of lamps they hold nowsupported only by the packing sheets. At this point the arms areretracted to the loading position to receive a fresh set of the lamps.

Platform 20 is now lowered by an amount approximating the combinedheight of the lamps and their supporting sheets, another pair of packingsheets is placed over the ends of the lowered lamps, and a fresh set oflamps is deposited on them by arms 10, 11 in the same way the first setof lamps was deposited. The platform is again lowered and a third layerof lamps placed over a third pair of packing sheets, the steps beingrepeated until a desired number of lamp layers, such as six, is reached.Now a seventh pair of packing sheets is placed over the sixth layer oflamps and the six-layer assembly is ready for insertion into a carton.

The cartoning can be effected by sliding the lowered six-layer assemblyendwise or backwards into open cartons held below the level of tables131, 132. There is sufficient engagement between the lamps and thepacking sheets to assure that the assembly slides into a carton withoutdislodging any of the sheets. Cartoning can also be accomplished bylifting the fully loaded platform to push the assembled layers of lampson it up into the open end of an inverted open carton, after which theplatform is pivoted around its far edge 29 to roll the inverted filledcarton over into upright position so that its covers can be fastened tomake it ready for shipment. The lamps so packaged are all cushioned attheir ends by the spacers, there being one spacer above and one beloweach lamp end. Each spacer has ribs that partially encircle each lamp,the ribs of the last pair of spacers partially encircling the same lampsthat are partially encircled by the ribs of the preceding pair.

FIGS. 2 and 3 show this lamp packing more fully. The packing spacers areeach identical and are shown in FIG. 3 at 30. They are molded from woodand/or paper pulp as generally rectangular sheets having a set of fivetransversely-extending parallel ribs 31, 32, 33, 34 and 35 standing upfrom its central portion, and upstanding walls 41, 42 that providerib-like packing surfaces which increase to 7 the number of parallelrib-like surfaces. These form a set of six channels 51, 52, 53, 54, 55,56 each of which receives one end of an elongated fluorescent light bulb15.

Along one long edge, the sheet 30 is formed into a shoulder 61 merginginto the successive rib structures to provide abutments that engage theend walls 60 of the fluorescent lamps but do not engage the terminalpins 19. Shoulder 61 is also shown as having transverse grooves 64, 65receiving those terminal pins and protectively extending beyond them.

The floor of the sheet can be stiffened somewhat by depressions 71, 72,73 distributed over it. These also provide shot plateaus 81, 82, 83 thathelp cushion the bulbs. Additional bracing can be provided by notches91, 92 molded in walls 41, 42 as well as in the ribs.

The ribs are shaped and spaced from each other to hold a fluorescentlamp cushioned so that less than half the lamp thickness rests in achannel 51, 52, etc. This leaves about half the lamp thickness exposedat each of the five lowest layers 101, 102, 103, 104, 105 of stackedlamps. The uppermost lamp layer 106 has the extra packing sheets 121,122 inverted over its lamp ends and these cover the otherwise exposedhalf thickness.

By using the above packing technique it becomes unnecessary to devise aspecial packing sheet with ribs in its upper and lower surfaces, and asingle type of standard packing sheet having all its ribs on one facedoes a very effective job. This also saves the extra packing height thatwould be required if the packing sheets had ribs on both their faces.

According to the present invention automatic feeders 201, 202 arearranged to automatically and successively place individual packingsheets on tables 131, 132 so that they can be conveniently moved by apacker into place on platform 20. These automatic feeders are shown asmirror images of each other and will now be described in detail inconnection with FIGS. 4 through 8.

Each feeder has a rigid low-friction support plate 210 of steel forexample, which holds a stack 212 of packing sheets all nested together.The stack is urged toward a stop frame 214 at one end of plate 210, by aset of belts 222 (FIGS. 6 and 7) each about 1/4 inch wide and spacedabout 21/2 inches from each other. These belts need not be flat, and areshown as standard round rubber belts mounted on pulleys 224 adjacentstop frame 214 as well as on another set of such pulleys at the otherend of the support plate. A slot can be cut out of the plate as at 226,to permit the pulleys 224 to be mounted under the plate with the beltsrunning through the slot. The belts are all connected for simultaneousstepwise actuation to move their upper flights toward the stop frame,thus carrying along the stack of packing sheets. This stack issufficiently light in weight that it does not cause the development oftoo much friction between the support plate and the stack-carryingbelts. The belts themselves, or their upper surfaces, are ofhigh-friction material such as rubber so that they very effectivelycarry and yieldably urge the packing sheets along toward the stop frame,but the stack-carrying belts slide easily over the low-friction supportplate. Moreover, the intermittent belt movement produces less wear onthe belts than continuous belt movement.

Stop frame 214 encircles the stack at the foward end of the supportplate 210. The frame has uprights 230 and a top bar 232, all spaced fromthe stack, and a bottom bar 234 the top of which is about 1/2 inch abovethe support plate. The front of the stack is held above plate 210 by thebelts on the belt pulleys and urged by the belts onto the top of thebottom bar 234.

A series of fingers 236 fitted to the uprights 230 and to the top andbottom bars 232, 234 extend toward the stack and help retain its leadingpacking sheet in place so that it does not fall off the forward end ofthe stack. These fingers each end about 1/16 inch in from the outermargins of the leading packing sheet, and can be pointed as shown tomore readily permit that sheet to be deliberately pulled forward fromthe stack when desired. Heavy aligning guides 238 can also be used tomake sure the individual packing sheets are properly aligned when theyreach the forward end of the stack.

A transfer carrier 250 is arranged to grip and pull the leading packingsheet from within the stop frame. The carrier is shown as having achannel-shaped holding bracket 252 fitted with three sets of grippingjaws 261, 262, 263 and mounted by a tubular connector 254 in a journalbearing 257 in a generally vertically oriented plate 258. That plate inturn depends from a supporting arm 259 clamped to one end of generallyhorizontal swivel arm 268 the other end of which is bent downwardly andis pivotally received in a box 270.

The downwardly bent end projects out through the bottom of box 270, asshown at 272 (FIG. 7) where a crank arm 274 is clamped to it, the crankarm in turn being connected for rotation by a bar 276 operated by ahydraulic cylinder 278 secured to the lower portion of the base on whichsupport plate 210 is held. Cylinder 278 is fitted with hydraulic lines280, 282 by which the arm 268 is rotated to bring carrier 250 againstthe leading spacer sheet on the stack, or back to a sheet unloadingposition shown in FIG. 4.

The tubular connector 254 is arranged for rotation by a hydrauliccylinder 284 which raises and lowers a rack 286 having teeth meshingwith a gear 288 fitted around the cylinder. This enables rotation of theholding bracket 252 180° and back around the axis of the tubularconnector, between the position shown in FIGS. 5 and 6 to theupside-down position shown in FIG. 4.

In the sheet unloading position illustrated in FIG. 4, the transfercarrier is over a discharge chute 289 fitted with a hydraulicallyoperated retractable dam 290 and a hydraulically operated retractablepush-rod 291. The chute leads down to table 132 where packing sheets aresuccessively delivered by the transfer carrier.

As shown more clearly in FIG. 5, the three sets of gripping jaws 261,262 and 263 are pivoted to the holding bracket 252 as by bolts 292 thatpenetrate through openings in generally horizontal flanges on thecarrier, and also penetrate through blocks 291 welded onto the rear ofeach jaw (FIG. 8). Spacers 289 can be slipped over each bolt above andbelow the block to hold the blocks at the proper level on the bolts. Themouths of every jaw are fitted with rows of needle-like teeth 293 thathave lengths about equal to or somewhat longer than the wall thicknessof a packing sheet. The teeth are also sufficiently narrow, about 1/32inch thick at their widest portion, so they readily penetrate the wallof a packing sheet without damaging it.

The jaws of each pair are biased toward each other by engaging springs294 hooked between ears 290 extending out laterally from each jaw, andare pushed apart by hydraulic cylinders 295 one of which is positionedinside the tubular mount 254. These cylinders have piston rods 256 thatengage cams 258 carried by each jaw where it faces its mating jaw, andmovement of the piston rods toward the jaws causes the rods to engageand push the cams, thus pivoting the jaws outwardly around the bolts292. This operation is more clearly shown in FIG. 8. As also shown inthat figure the jaws are held in a jointly floating relation by theirsprings 294 and readily adjust themselves to properly engage a rib as at31, even though the rib is not symmetrically spaced with respect to bothjaw pivots. Molded pulp articles inherently tend to have substantialamounts of dimensional variation.

The mouths of the jaws are also shown as carrying on their outer facessets of spacers 296 that assure the disengagement of the jaws from apacking sheet, although this feature is not essential. Also the jaws canbe further fitted with guides 297 that engage and guide a packing sheetwhen it is released by the jaws, to assure that it falls free and itsshoulder 61 does not get hung up on the top corners of those jaws. Inthe illustrated construction, those guides are only provided on theouter sets of jaws 261, 263, and only on the inner jaws of those twosets. It is preferred that the transfer carriage be tilted a fewdegrees, 8 to 10 for example, away from the exact vertical, as moreclearly shown in FIGS. 4 and 6. This helps assure that the packingsheets drop onto the chutes 289 with the same face up.

An additional hydraulic cylinder 298 (FIG. 8) is also fitted to thelower portion of the base for support plate 210, and is connected toratchet a one-way clutch 299 that drives a chain-and-sprocket assemblyto rotate the forward pulleys 224 of the advancing belts 222.

All of the hydraulic cylinders are connected in parallel to a standardhydraulic pump and fluid return system containing electrically operatedvalves that separately effect cylinder actuation. A variable speedcycling switch is arranged to bring about the following sequence:

a. rotation of the transfer carriage to a position against the leadingpacking sheet on the stack while the gripping jaws are held in openedposition;

b. release of the opened gripping jaws so they are moved by theiractuating springs to engage the forwardly projecting walls of the ribson that sheet. As noted above, the individual jaws are not in fixedorientation on the holder 252 but that any of the pairs of jaws canrotate a bit around their pivots to adapt to minor variations in theshape and location of the rib walls;

c. rotation of the transfer carriage with the gripped sheet back to thesheet unloading position over chute 289 (FIG. 4);

d. movement of the gripping jaws to their opened positions to releasethe gripped sheet. This release is made fool-proof by the spacers 296which upon opening of the jaws engage the walls of the sheet adjacent tothe rib wall in which the jaw teeth are inserted. By such engagement onjaw opening, the sheet is kept approximately centered with respect tothe jaws so that it cannot be shifted any significant distance laterallyon the teeth of the three left-hand jaws of each set, for example, asthe jaws are opened. Such lateral sheet movement would permit the teethof the right-hand jaws to disengage from the walls in which they wereinserted, but could leave the teeth of all left-hand jaws still insertedin the sheet and thus keep the sheet from dropping onto the chute;

e. actuation of belt advance by reciprocation of cylinder 298. This neednot be a separate step and can be conducted during any of steps (b), (c)or (d);

f. repetition of the foregoing sequence of steps except that everyseventh sequence is modified by

I. conducting its step (c) so that rotation of the transfer carriagewith a gripped sheet back to the sheet unloading position is accompaniedby revolving of carriage holder 252 180° around the tubular connector254 to rotate the gripped sheet side for side,

Ii. conducting its step (d) to open the gripping jaws while raising dam290 so that it catches the unloaded sheet and holds it on the chute withthe trailing portion of the sheet over the push-rod 291,

Iii. then reciprocating the push-rod to tilt the sheet thus positionedover the dam and invert it front-to-back as the sheet slides intoposition on table 132 in side-to-side inverted relation as compared tothose arriving there in the preceding six sequences; and

Iv. retracting dam 290, a step which is preferably effected while thetransfer carriage goes through step (a) of the next sequence.

The seventh sequence carried out in the foregoing manner takes a littlelonger than any of the first six sequences because of the added timerequired to invert over the dam the sheet being delivered. The addedtime delay can be as little as a fraction of a second, and may bedesired to help the packing operator recognize the seventh sequence sothat he can correlate it with the completion of a stack of lamps. Ifsuch recognition is not desired then the packing can be speeded up byspeeding up steps (a), (b), (c) and/or (d) of the seventh sequence sothat the seventh sequence requires the same or even less time than eachof the first six.

The packing sheet delivery can also be synchronized with the packing asby providing an easily moved switch arm 299 over a portion of table 132onto which a packing sheet lands when discharged from chute 289 and fromwhich the sheet is moved when it is removed from the table, andconnecting that arm so that it actuates a switch 300 that triggers thestart of a feed sequence whenever a packing sheet is removed from thetable. Such sequence triggering can cause a sequence to start at step(a), or at step (d). The latter arrangement is particularly desirablefor maximum packing speed inasmuch as the apparatus can then beconnected to automatically go through its sequencing at maximum speed,but automatically stopping at the completion of step (c). This makes afresh packing sheet ready to immediately drop onto table 132 as soon aspossible after the previous packing sheet is removed. The entireequipment is then automatically controlled by the packing individualwithout requiring him to go out of his way, or to set or reset timers orthe like.

To effect such automatic synchronization, the actuation of the cylindersthat open the gripping jaws is arranged to automatically close a switch303 that actuates cylinder 278 to rotate the transfer carriage to theface of the stack. A pin 305 standing up from the piston rod 256 of oneof the jaws can be conveniently used to operate switch 303. It ishelpful to have such a switch incorporate a little delay in theactuation of the carriage rotation, to assure that the packing sheetreleased by the jaw opening has time to fall free of the carriage beforethe carriage rotation can deflect the fall away from chute 289.

A switch such as shown at 301 in FIG. 4 is actuated by the downwardlybent portion of swivel arm 268 when that arm is rotated enough to bringthe carriage against the stack, and retracts the jaw cylinders to causethe jaws to be moved into gripping position by springs 294, to thus gripthe leading sheet.

Completion of the retraction of the jaw cylinders then automaticallyactuates cylinder 278, as through switch 303, to return the transfercarriage to the sheet release position in which position the apparatuscan remain until the previously released sheet is removed from table132. Switch 300 tripped upon such removal can be self-resetting or canbe reset by the arrival of the carriage at the stack.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:
 1. An automatic feed apparatus for supply packingspacer sheets one at a time to a packing station, said apparatusincluding a stack holder that holds a stack of spacer sheets with theend spacer of the stack in a predetermined feed location, a transfercarrier shiftably mounted for movement between a first location adjacentsaid predetermined location for gripping the end spacer sheet and asecond location where it drops the gripped spacer sheet, a chute underthe second location to catch the dropped spacer sheet and slide it downforwardly to a pick-up station, and sheet inverting means connected toautomatically rotate predetermined spacer sheets about half a revolutionaround an axis generally perpendicular to these sheets and also flipthese sheets over front-to-back so that they reach the pick-up stationso inverted.
 2. The combination of claim 1 in which the inverting meansincludes (I) a first means for rotating the transfer carrier about halfa revolution around said axis so that the rotated sheet drops into thechute after having been rotated about 180°, and (II) additional meansarranged to flip the sheet over front-to-back as it moves down thechute.
 3. The combination of claim 2 in which the sheet flipping meansincludes (I) a sheet-stopping dam in the chute retractable out of theway of a sheet that has been dropped and actuatable for automaticinsertion into sheet-stopping position, and (II) a pusher that is alsoretractable out of the way of a sheet that has been dropped andactuatable for automatic projection against the rear of a sheet that hasbeen stopped by the dam to push that rear far enough to flip the entiresheet front-to-back over the dam.